Furnace fan and filter



Jan. 12, 1932. F. E. GRUNWALDT FURNACE FAN AND FILTER Filed April 4. 1928 4 Sheets-Sheet mat N701? f'mnktifirmna/df r A T TORNE Y Jan. 12, 1932.

F. E. GRUNWALDT FURNACE FAN AND FILTER Filed April 4. 1928 4 Sheets-Sheet 2 A TTORNEY Jan. 12, 1932- F. E. GRUNWALDT FURNACE FAN AND FILTER Filed April 4, 1928 v 4 Sheets-Sheet 3 ATTORNEY 1932- F. E. GRUNWALDT FURNACE FAN AND FILTER Filed April 4. 1928 4 Sheets-Sheet 4 Fig. 1a

' v INVENTO/l Fmnkfi'runwa/df A TTORNEY Patented Jam l 2; 1932 i rnanknonunwn'mr, or anemia, wasnmo'ron' runnacn ran Ann FILTER,

The invention is a forced draft fan in. combination with a housing and a filter andin which the housing is constructed to provide a by-pass so that the area of the duct in which the fan is located will not be reduced when the fan is stationary. I

The object of the invention is to provide a forced draft fan in combination with a housing which may be located in; a furnace intake air duct which is also constructed so that. the

fan will not reduce the area of the duct when not in use,

/ Another object of the invention is to provide a forced draft fan housing having means for filtering air passing therethrou h.

Another object of the invention to pro:

'vide a forced draft fan housin in which the pglrts are readily removable an interchange- Anotherobject of the invention is to provide a filter for a forced draft fan which is simple, economical and efiicient.

Another object-of the invention is to revideja- .filterfor a forceddraft fan whic is readily removed and cleaned.

Another object of the invention-is to pro- -vide a filter for a forced draft fan which may be automatically operated'and cleaned. I

Another object of the invention is to provide suitable bearings for a forced draft fan which will absorb the vibrations ofthe fan.

Another object of, the invention is to provide bearings which are adaptable to absorb,

vibrations in which the wear may readily be taken up.

A further object of the invention is to pro vide a forced draft fan housing having a bypassaround the fan with a bafile to open or close the by-pass which may operate automatically or be operated manually.

A still further object of the invention is to provide a forced draft fan in which air enters at the ends of the blades and which is provided with a disc forming a closure adjacent the center to prevent air travelling through the fan lengthwise of the blades.

And a still further object of the invention is to provide a forced draft fan which is of a simple and economical construction.

With these ends in new the invention embaflle adaptable to close the attac housing reverse: so that the air will enter fjfilter shown in Figures '9 an 11.

1828. Serial '30. 267,465.

bodies a fan housing, a fan positioned within the said housing, an inner removable housing cooperatin with the fan, suitable bearings for the an which are adaptable to absorbthe yibrations thereof, an adjustable passage around the fan and a suitable filter.

Other features and advanta es of the invention will appear from the ollowin description taken in connection with the awo0 ings, wherein p igure 1 is a cross section through the fan, housmg and filter.

Fi ire 2'is a front view of the fan shown the positionof the filter.

Figure 3 is a view showing the fan with discs upon which the blades are '-mounted which IS an alternate arrangement to that shown in Figure 1.

Eifile 4 is a detail showing the'means of mg the blades to the discs. p Figure 5 is a view similar to that shown in Figure 2 showin a double fan with the inner the fan blades from the center ofthe housing .and be discharged through two independent openings or ducts.

Fi ure 6 is a sectional plan showing the positlons of the inner housing of the fan .80 shown in Figures 1 and 2. I

Figure 7 is a. similar view showing the position of the inner housing of the fan shown in Figure 5.

- igure 8 is a view showing an alternate design of the filter shown in Figure 1 in which I the filter is made in a frame which is adaptable to slide into the housing. A Figure .9 is a view showing a fan housing ofja slightly difierentdesign which is pro vided wlth a movable filter.-

Fi re 10 is a front view of the fan shown in Flgure 9 with part broken awa Figure 11 is a view showing a an of another alternate design and in which the lower end of the filter extends into a water pan.

Figure 12 is a front view of the design shown in Fi re 11.

Figure 13 1s a view showin a detailof the 00 in Flgure 1 with part broken away to show 65 Figure 14 is a detail showing the inner removable housing shown in Figures 9 and 11.

Figure 15 is a detail showing a bead formed at the edge of the filter which holds the filter upon the roller;

Figure 16 's& ed e of the inner fan housing.

Figure 17 is a detail showing an end view of the vibration absorbing bearing.

detail showing a bead at the Figure 18 is a sectional plan throughthe.

bearing. a Figure 19 is a side elevationof the bearing. In the drawings the device is shown as it would be made wherein numeral 1 indicates 3the filter. M

The housing 1 may be made as shown in Figures 1, 5, 9 or 11 as it will be understood a by-pass in the intake ductof a urnace, around the fan and which is also adaptable to accommodate an inner housingaround the fan which is arranged to permitthe fan to function. 7 v v In the desi shown in Figure'sl and 2 the housing 1 is made with side lates 4 and 5,

i a cover 6 and a bottom 7. The ottom curves upward at the rear as shown in Figure 1 and extends to a point 8 where it is bent as shown to provide a recess 9 on the under} side and a recess 10 on the u per side. A back late- 11 may be positione at the rear of the ousing with its lower edge in the recess 10 and its.

upper edge provided with a flange 12 having a recess 13at the front and a recess 14 at the inner side as shown. Above the flange 12 is I a channel shaped member 15 having flanges 16-and 17 at the ends. The flange 17 is adaptable to be held in the recess 13 and the flange 16 is adaptable to be held in a recess 18 in a flange 19 at the lower edge of the upper back with a clip 21 which positely positioned recess 25 in which the en s of semi-circular members 26 and 27 may be held and the opposite ends of the members 26 and 27 will be held in the recess 9 at the upper edge of the bottom plate 7. The ends'of these members may be held in the recesses by bolts 28 as shown or in any other suitable manner.

- 26 and 27 'form an inner housing around-the .mwfan bladesand in the design shownkin Fig tends over the blades and the lower portions It will be observed that as the bolts are removed and' interchanged. The members 22,

um ffli'iipper portion 22 of this housing exthe housing, numeral 2 the fan-and numeral that-the purpose of the housing is tofprovide moved these members may readily be re- 26 and 27 are positioned beyond the ends of the blades so that air passing downward through theduct will pass into the ends of the blades and then be forced out throu h ,the center of the housing, asindicated by t e arrows; whereas these members may be interchanged as'shown in Figure 5 with the fan divided into two parts as indicated by the numerals 29 and 30, and in this arrangement the member 22 will be placed on the lower side of the fan and the members 26 and 27 on the upper sides of the fans so that the air will be drawn into the fan blades from the center and discharged through two independent openings at the sides.

' At the front of thefan housing is a bafile plate 31 which is pivotally mountedon a shaft 32 and adaptable to rest upon stops 33 at the sides. At the end of the shaft 32 is an arm 34 having a weight 35 upon it which may readily ance t built up on the air leaving the fan or if the be adjusted by a set screw 36 to bale baflie 31 so that as a back pressure is volume of the suction should increase the baflle 31 will automatically raise and force all of the air through the fan. Thearm 34.-

is also provided with a recess 37 in which the end 38 of a rod 39 extends and the other end of the arm 39 is pivotally attached to a lever 40 which is pivotall mounted on the side of the fan housing at t e point 41 and it will be observed that as the lever 40 is raised it will raise the bafile 31 whereas, as the end 38 is not. attached to the arm ,34 the bafile 31 may automatically rise indep ndent of the manual means for operating it. It is understood that this bafile may be used in any of the designs hereinafter described.

The fan 2' is made with blades 42 which are formed of flat plates with their outer edges curved sli htly forward to form ti 43 and these bla es may be attached to hub: 44 on a shaft 45 through arms 46 as shown in Figure 1 or attached to discs 47 which are mounted upon the shaft 45 through hubs 48 as shown in Figure 3, or in any other suitable manner. In the design shown in Figure 3 the discs 47 are provided with o nings 49 the material from which ex'ten outward to form flanges 50 to which the blades 42 may be attached by rivets or bolts 51 as shown in Figure 4. It is understood that although the fan is'shown and described. as being made in this manner'it may be made in may other suitable manner or any other suita type of fan may be used.

In the design shown in Figure 1 the filter 3 is formed with'a flat piece of textile material with a rod 52 atone endand the opposite" I end fastened overhooks 53 as shown. The

edges of the filter are held in channel shaped members'54 and55 as shown in Fi res 1 and 2 and the housing is also provide with stays 56 which will support the central part of the filter. Cords 57 and 58 may also be attached to the back of the. frame and extend forward around the lower end of the filter and then backward over the filter where the ends which are indicated by the numeral 59 may be held as shown in Figures 1 and 2 so that when it is desired to remove the filter the ends 59 of the cords may be pulled out. and'the cords will cause the filter toroll up on ,the rod 51. The rod 5l-1nay be of sufiiclent weight to unroll the filter by rolling downward in the channel shaped members 54 and 55 when the filter is replaced. It is understood however that the filter may be provided with a solid frame as shown in Figure 8 or may be made as shown in Figure 13 or in any other suitable manner.

In the design shown in Figure 13 the filter is made with a continuous piece of fabric and mounted upon an upper roller 61 and'a lower roller 62 with the upper roller mounted in the upper end of a frame 63 and the lower roller adaptable to rotate freely in the lower end of the frame. enlarged at the center as shown inlFigure 13 which will take up the stretch in the central part of the filter and the ed es. of the filter fabric are made as shown in igure 15 with a roll 64 which extends over the edges of the rollers and which will have a tendency to hold the filter upon the roller or prevent its working 011' of either end. The frame 63 may be made in. any suitable manner and provided with opening 65 in both sides so that air may pass through the openings in both sections of the filter. The lower end of the frame may be provided witho nings 66 which provide a drain when the filter is used wet as shown in Figures 9 and 11. In the design shown in Figure 9 the filter is arranged in a vertical p position at the rear of the fan housing and the upper part of the frame is provided with a perforated pipe 67 which may spray water upon the filter on the roller 61 to kee the filter moist and in the lower end of the rame is a brush or pad as indicated by the numeral 68 which will clean the filter. In the design shown in Figure 9 the water may be permitted to flow away from the lower end of the filter. In this design the roller 61 is provided with a pulley 69 which is continuously driven b a motor 70 through reduction gears as in icated by the numeral 71. It is understood that the gears and motor may be arranged in any suitable manner and any suitable means may be used for connecting them to the roller 61.

In the design shown in Figure 11 the roller I 61 is provided with a crank 72 so that it may be operated by hand and a pan 73 is provided in the lower end of the filter which may contain a supply of water so that the loweriend of the filter will pass through water as its osition is changed. In the design shown m Figure 13 the end of theroller 61 is provided with a ratchet gear74 which is operated The lower roller 62 is-slightly driven by a motor 79 or in any other suitable manner.

In the design shown in Figures 9 and 10 the fan'is positioned in an inner housing 80 as shown in Figure 14 which is installed in an outer housing 81 and the outer housing is made somewhat longer than the fan as shown in Figure 10 so that air may enter the fan blades at the ends and be. forced forward as the blades rotate through an opening 82 at the center of the housing. The housing 81 is soarranged that the inner housing 80 may be withdrawn through therear when the filter is removed. In this design the rear ofthe inner housing 80 may be provided with struts 83 which will hold the housing in relation to the fan and outer housing shown inFigure 11 the inner housing may be fastened to the outer housing by bolts 84 at the front as shown. In the design shown in Fighres 11 and 12 the housing is similar to that shown in Figures 9 and 10 except that the inner housing is positioned toward one side of the outer housing so that a by-pass will be provided atone side which is shown by an opening 85 in F igure12. In this design the inner housing 80 is provided with a flange 86 at one side which holds the housing a short distance from the end of the outer housing so that air may enter through the ends of the blades. It is a so understood that the housings may be arranged and positionedin any. other suit able manner.

The inner housing 80 is shown in detail in Figure 14 in which it will be observed that it'is provided with side walls 87 and 88 having circular openings 89 and at the upper end is a flat cross member 90 having openings 91 through which the bolts 84 pass and from the rear of the member 90 is a curved plate conforming to the riphery of the openings 89 and extending ownward tothe point 92 which form the lower ends of the sides 87 and 88. The edges of the openings 89 are provided with rolls 93 as shown in Figure 16.

Figures 17, 18 and 19 show details of the vibration absorbing bearing which is made with a c lindrical member 94 through which the sha 45 passes. The member 94 is provided with trunnions 95 at the sides having and 102 having inclined edges and the member 99 is provided with tongues 103 and 104 also having inclined surfaces corresponding with the slots 101 and 102 and positioned as shown in Figure 17 so'that as the members 99 and 100 are drawn together the inclined surfaces will move each toward the center so that the recesses will grip the members 98, and it will be observedthat as the members 98 wear the members 99 and 100 may be drawn closer together to hold them rigid. At the ends of theniembers 99 and 100 are openings 105 and 106. The 0 openings 106 inthe members 100 are slotted to provide further lateral movement of the members as they are drawn. together. Bolts 107 may be placed through these 0 enings which. will hold the bearing and t rou h which the wear of the caps 98 may also taken up. It is "also understood that the specific details of this bearing are immaterial as other means may be used for drawing the two members together, or for drawing each toward the center as they are drawn together.

It will beunderstood that changes may be made in the construction without departing from the spirit of the invention. One of which changes may be. in the relative .posi-' tionsof the fan, inner housing and filter in relation to each other or to the outer casing; Another maybe in the use of a fan of a difierent type, another may be in the use of a different type of filter, and still another may be in the change of the designs ofeither the outer or inner housings.

The construction will be readily understood from the foregoing description. In

""use-thefan may be positioned as shown and it will be observed that as it rotates air will be drawn in through the ends of the blades and forced out through the centers of the blades and as it is drawn in through the filter it will be'thoroughly cleaned: .The filter may be readily removed and cleaned or may.

be used dry as may be desired. The entire filter frame as shown in Figure 13;i s$ readily removable from the housing shown"ii1i Figures 9 and Hand it will be observed that as this frame is raised in the design shownin. Figure 11 the water pan 7 3 may readil be removed. The filter may, also be rea i1 removed from the frame as the upper rol er is positioned in slots as-sho'wn and the lower .1 roller hangs free-in the frame. The lower roller should be of substantially a heavy material to hold the filter smooth. Either roller however may be made of any suitable material. It will also be observed that the wet screen or filter ma be used in the path of the outoing gases rom the furnace to catch spar s if desired.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent, is:

nings 105 in the mem-- bers 99 are vsubstantially round whereas the .the ,fan is started.

1. In a device of the class described a fan, acircular housin around the said fan aving anopenin in t elower part of the front thereof, said circular housing extending be-' yond the ends of the fan with the lower part of the front closed and the upper part beyond the ends of the blades 0 en, and an outer housing in which the said ormer housing is removably mounted. v

' 2. In a device of the class described, a fan,

a circular housing around the said fan having an opening in the lower part of the front thereof, said circular housing extending beyond the ends of the fan with the lower part of the front closed and the upper part beyond the ends of the blades 0 n, and an outer housing in which the said former housing is removably mounted, said outer housing havin a suitable passage to permit air to pass t erethrough around the fan.

3. In a device of the class described, a fan rotor, an outer casing surrounding the said fan rotor and in wh1ch the rotor. is rotatably mounted, an inner removable casing surrounding and cooperating with the sai fan, said outer casing being of suflicientsize to permit a bypass air passage around the said fan rotor and inner'casing, a bafile plate for closing the said bypass passage between the said innerand outer caslngs, means for pivotally supporting the said bafile plate from one side to permit it to hang downward 1n the path of air from the fan rotor, means for counterweightin the said bafile, and manual means for a 0 operating the said baflle, said 'counterwei ht being sufiicient to permit 'the said be e to automatically adjust itself to close the said bypass when 4. In-a fan of the character described, a fan, a circular housing around the said fan having openings in the ends thereof, an outer housing around the said circular housing and extending beyond the ends thereof, the ends of thesaid outer housing being closed and arranged to permit circulation from the said outer housing into the ends of the said circular housing, said outer housing having an inlet opening in the periphery thereof and said circular housing having an outlet opening in the periphery thereof, and means for readily removing the said circular hous- 1n the passage for closing the same when l the velocity of air passing through the fan reaches a predetermined amount.

6. In a device of the class described,- a fan, a circular housing around the said fan having an opening in the lower part of the front thereof, said circular housing extending beyond the ends of the fan with the lower part of the front closed and the upper part beyond the ends of the blades open, an outer housing in which the said former housing is removabl mounted, said outer housing having a suitable passage to permit air to pass therethrough around the fan, a balanced baflie pivotally mounted in the said housing and adapted to close the said passage, and

means for operating the said bafiie to close the said passage when the velocity of air passing through the fan reaches a predetermined amount.

FRANK E.. GRUNWALDT. 

